Podocyte injury and its association with proteinuria in IgA nephropathy / 中华肾脏病杂志

Objective To investigate the injury of podocyte and its association with proteinuria in IgA nephropathy (IgAN). Method Thirty-five patients of IgA nephropathy with proteinuria more than 1.0 g/24 h were enrolled in the study, and eight cases of renal harmatomaeetomy or renal cancinomaectomy were as controls. Cell cycle regulatory proteins (p21, p27), podocyte-associated molecules (integrin-β1, nephrin, α-actinin 4, nestin), foot process width (FPW) and the amount of podocyte were examined by immunohistochemistry and real-time PCR, respectively. Patients were divided into two groups according to podocyte number per volume (Nv): podocytopenia group (n=15, Nv<52.49×106/μm3) and normal number group (n=20, Nv≥52.49× 106/μm3). Proteinuria was followed up for eighteen months. Results Compared with the controls, podocyte p21 was re-expressed, while the expression of p27 was decreased (0.71±0.12 vs 0.91±0.07, P<0.05) in IgAN. The nestin protein level was markedly decreased in IgAN (13.4%± 0.04% vs 17.6%±0.04%, P<0.05). The mRNA expression of integrin-β1 was significantly increased (12.54±5.20 vs 1.02±0.30, P<0.05), while the amount of nephrin, α-actinin4 remained unchanged. Effacement of foot processes and podocyte detachment from the glomerulax basement membrane were observed in some cases. Nv was significantly less than that of controls (161.27± 225.92 vs 323.22±138.12, P<0.05), which was associated with the Lee's grade of IgA nephropathy. The integrin-β1 mRNA expression and Nv were negatively correlated with baseline proteinuria by univariate analysis (r=-0.840, P=0.034; r =-0.4483, P=0.014, respectively). Proteinuria in podocytopenia group was decreased more slowly than that in normal number group. Conclusions Podocyte injury exsists in IgAN with proteinuria, which manifests alterations in cell cycle regulatory protein and some podocyte-associated molecules, as well as foot process effacement and loss of pedocyte. Podocyte injury may be involved in proteinuria by affecting the progression of proteinuria in IgAN.

Change of glomerular renin-angiotensin system expression in angiotensin type 1a receptor gene knockout mice and its effects on extracellular matrix remodeling under diabetic condition / 中华肾脏病杂志

Objective To explore the glomerular change of renin-angiotensin system (RAS) expression in ATIaR gene knockout mice and its effects on extracellular matrix (ECM) remodeling under diabetic condition. Methods ATlaR knockout mice were generated previously. Hyperglycemia was induced by peritoneal injection of streptozotocin in ATIaR knockout mice and wild type mice. Normal AT1aR knockout mice and wild type mice were used as control group. Twelve weeks later, kidneys were harvested and frozen quickly in dry ice-acetone. Glomendi were collected by laser capture microdissection and total RNA was extracted, mRNA expression of AT1aR, AT1bR, AT2R, angiotensinogen, ACE, renin, and CYP11B2 was assessed by real-time PCR. ECM accumulation was evaluated by PAS staining. Protein levels of transforming growth factor β1(TGF-β1), type 1 plasminogen activator inhibitor(PAI-1), monocyte chemotactie protein 1(MCP-1) and renin were semi-quantitated by immunostaining. Results Compared to the wild type, mRNA expression of AT1bR, angiotensinogen, renin, CYP11B2 within glomeruli was upregulated significantly in ATlaR knockout mice (P<0.05), but no change of ACE expression was found in these two groups. AT2R protein was poorly detected in AT1aR knockout glomeruli and downregulated in wild type glomemli. ECM accumulation was significanfly increased associated with the parallel increase in TGF-β1, PAI-1, MCP-1 and renin within glomendi (P <0.05). Conclusions AT1aR gene knockout cannot improve ECM deposition in diabetic nephropathy. The compensate change of RAS components may be involved in this scenario: upregulation of AT1bR, downregulation of AT2R. CYP11B2 and renin may function in a novel pathway.

Endothelin receptor antagonist combined with a calcium channel blocker attenuates renal injury in spontaneous hypertensive rats with diabetes / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the effects of the mixed endothelin receptor antagonist, bosentan, combined with the long-acting calcium channel blocker, amlodipine, compared to the angiotensin-converting enzyme inhibitor, cilazapril, on the progressive renal injury in spontaneous hypertensive rats (SHR) with diabetes.</p><p><b>METHODS</b>Diabetic hypertensive rats (SHR-DM) were induced by streptozotozin injected in male SHR (7-week-old),and divided into an untreated and three treated groups: 1) cilazapril treated group; 2) bosentan+amlodipine treated group; and 3) amlodipine treated group. Wistar Kyoto rats (WKY) and SHR rats served as normotensive and hypertensive control, respectively. The mean arterial blood pressure, renal function, endothelin and angiotensin II levels as well as the protein expression of renal extracellular matrix components and transforming growth factor (TGF)-beta1 were determined at the end of the 4th week.</p><p><b>RESULTS</b>Mean arterial blood pressure significantly increased in SHR and SHR-DM rats compared to WKY rats. All the therapies reduced the blood pressure to normal levels. However, the enhanced urinary protein excretion, the decreased creatinine clearance as well as the increased plasma and intrarenal endothelin and angiotens in II levels were found in the untreated SHR-DM and prevented by treatment with bosentan+amlodipine and cilazapril. Similarly, these two kinds of therapies in SHR-DM abolished the overexpression of renal TGF-beta1 by Western blot analysis and reduced the accumulation of collagen type IV, laminin and fibronectin proteins by an immunochemical approach. Amlodipine monotherapy had no detectable effects on the above parameters.</p><p><b>CONCLUSION</b>Bosentan combined with amlodipine can offer similar renoprotective effects on that of cilazapril and may be a potent therapy to attenuate renal injury by reducing renal protein levels of TGF-beta1 in diabetes with a hypertensive state.</p>

Deposition of ox-LDL on uremic vessel wall and its influence on vascular remodeling / 第二军医大学学报

Objective:To determine whether ox-LDL (oxdized low-density lipoprotein) is highly deposited on the uremic vessel wall and its influence on the vascular remodeling. Methods: Segments of radial arteries were obtained from 21 uremic subjects during the operation of A-V fistula prior to hemodialysis. Segments of internal thoracic arteries of similar diameter were obtained from patients with benign chest tumors as control.The vascular lesions and ox-LDL, CD68,MCP-1, eNOS,ET-1, PCNA,FN on the vessel wall were determined by means of H-E stain and immunohistochemistry. Results： With H-E stain,atherosclerotic plaques were found in the radial arteries of 4 uremic patients. The middle layer of the arteries in uremic patients were obviously thickened, and the T/D　(thickness of the wall/external diameter) ratio was significantly higher than those in control group(P<0.01). ox-LDL,CD68,MCP-1, ET-1, PCNA,FN on the vessel wall in uremic patients were much higher than those in control group (P<0.01). Moreover, ox-LDL on the vessel wall was positively related to the expression of other above mentioned substances on the vessel wall (P<0.01). Whereas the expression of eNOS on the vessel wall was lower than control group (P<0.01),and was negatively related to ox-LDL on the vessel wall(P<0.01). Conclusion: ox-LDL is an important factor contributing to uremic vascular remodeling by increasing the migration,adhesion and infiltration of monocyte,the proliferation of vascular smooth muscle cell and dysfunction of endothelia.

Nephroprotective effect of mycophenolate mofetil on rat remnant kidney / 中华肾脏病杂志

ObjectⅣe To investigate the nephroprotectⅣe effect of mycophenolate mofetil (MMF) on 5/6 nephrectomized rats and explore its mechanism. Methods The 5/6 nephrectomized SD rats were used. After the operation, 15 mg/kg MMF, 25 mg/kg fosinopril (F) and 15 mg/kg MMF+25 mg/kg fosinopril were respectⅣely delⅣered daily by gavage for 8 weeks. Urinary protein, BUN, serum creatinine were measured at the end of the study. Renal pathological changes were evaluated and immunohistochemistry was used to examine the expression of fibronectin (FN), collagen Ⅳ, macrophage chemoattractant protein 1 (MCP-1) and proliferating cell nuclear antigen(PCNA) . RT-PCR was used to examine the TGF-?1 mRNA and TIMP-1 mRNA in the cortex of the kidney. Results Compared with the untreated 5 /6 nephrectomized group (NX group), urinary albumin excretion of MMF, MMF + F or F treated rats were substantially decreased [MMF: (116. 1?12. 5) mg/24 h, F: (95. 3?13. 8) mg/24 h, MMF + F: (73. 2?16. 3) mg/24 h vs. NX: (205. 6?16. 8) mg/24 h. P

Role of inflammation in the vascular lesions of uremic patients and its mechanism / 中华肾脏病杂志

10 mg/L) and group B(CRP